tree cbf3118efa4f2f6a8d8198c9e594d666fb8388e5
parent 47e81a2596b00ee7aaca58716ff164a1708b0b29
author Jeff Sharkey <jsharkey@android.com> 1477946029 -0600
committer gitbuildkicker <android-build@google.com> 1480632402 -0800

Public volumes belong to a single user.

When a public (vfat) device is inserted, it's strongly associated
with the current foreground user, and no other users should be able
to access it, since otherwise that would be a cross-user data leak.

To use the device under a different user, switch users and then
eject/remount the device.

Test: verified user isolation of USB drive
Bug: 32523490
Change-Id: I590c791996f1fea8d78f625dc942d149f1f41614
(cherry picked from commit 8b38d083c42e2706e1ff5a1410fa61d1f5dea3f5)